title: Perineal trauma in women undergoing vaginal delivery following intra-uterine fetal demise: a case-control analysis.
abstract: OBJECTIVE
  This study aimed to evaluate any differences in the incidence of perineal trauma in women undergoing vaginal delivery following intrauterine fetal death (IUFD) versus live-births. This information would be of interest in evaluating the possible effect of fetal demise on the mechanism of labour in the second stage and thus may provide invaluable insights to contribute to our understanding of the impact of fetal tone on the mechanics of labour and delivery.
  
  
  METHODS
  323 women who delivered vaginally following IUFD were matched with 1,000 women with a live-birth for age, parity, gestation and birth weight. Women undergoing assisted vaginal delivery and/or episiotomy were excluded.
  
  
  RESULTS
  Women with an IUFD had a significantly lower risk of perineal trauma overall (relative risk 0.16) as well as a lower risk of obstetric anal sphincter injury specifically (RR 0.12).
  
  
  CONCLUSIONS
  Women delivering vaginally after IUFD have a lower incidence of perineal trauma compared with women delivering a live infant. This may be due to differences in biomechanics following an IUFD.
authors.affiliation: Department of Urogynaecology and Pelvic Floor Reconstructive Surgery, St. George's Hospital, London, SW17 0QT, UK, mayabasu@aol.com.
authors.forename: M
authors.initials: M
authors.lastname: Basu
authors.forename: S
authors.initials: S
authors.lastname: Mukerji
authors.forename: S K
authors.initials: SK
authors.lastname: Doumouchtsis
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000293:injuries*; D016022:Case-Control Studies; D036861:Delivery, Obstetric / Q000009:adverse effects*; D005260:Female; D005313:Fetal Death; D006801:Humans; D015994:Incidence; D010502:Perineum / Q000293:injuries*; D011247:Pregnancy; D017695:Soft Tissue Injuries / Q000453:epidemiology* / Q000209:etiology; D050497:Stillbirth; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult